1. Field
Aspects of the present invention generally relate to an image forming apparatus which includes a storage portion for temporarily storing a sheet on which an image is formed within the image forming apparatus.
2. Description of the Related Art
Conventionally, there has been an image forming apparatus such as a copying machine or a printer which includes a storage portion for temporarily storing sheets within the apparatus so that a user can receive only the user's sheets while the user's sheets on which images are formed are prevented from being seen by other users.
Japanese Patent Application Laid-Open No. 7-125909 discusses an image forming apparatus which includes a plurality of storage portions for temporarily storing sheets on which images are formed within the apparatus in addition to a normal discharge tray disposed on an upper surface of the apparatus main unit shared by a plurality of users. The sheets stored in the storage portions cannot be seen from the exterior of the apparatus. Further, in the above-described image forming apparatus, a plurality of the storage portions is allocated to the users so that the sheets are sorted into different storage portions for the respective users. In order to receive the sheets, the user gives a discharge instruction to the image forming apparatus, so that the sheets stored in the storage portion corresponding to the user who gives that discharge instruction are discharged to the exterior of the apparatus. With this operation, the user can receive only the user's sheets while the user's sheets on which images are formed are prevented from being seen by other users.
In the configuration in which the storage portions are disposed within the apparatus as discussed in Japanese Patent Application Laid-Open No. 7-125909, the number of sheets storable in the storage portion has an upper limit. Therefore, in Japanese Patent Application Laid-Open No. 7-125909, when the user instructs the image forming apparatus to store the sheets more than the upper limit of the storage portion, the sheets are discharged to a normal discharge tray, or the image forming processing with respect to the sheets is not executed while the user is given a message indicating that the sheets cannot be stored in the storage portion. However, if the sheets are discharged to the normal discharge tray, it is not possible to achieve the original purpose of preventing the sheets on which images are formed from being seen by other users, and not only that, there is a problem in that the user's sheets and other user's sheets are mixed with each other. Moreover, productivity thereof will be naturally lowered if the image forming processing is stopped.